How I got out of PMI could vary from company to company.
I had a conventional loan and got out of the PMI last year pretty easily. (if you have been wanting to refinance, this is the time to look into that.)
But for my loan company, you had to bring the loan to value (believe that was term) to 78%. The reason why it was 78% and not 80% like most would imagine was due to me attempting to remove the PMI before 2 years had past from the origination of my loan.
If you are not looking to refinance, call your company (to find out their rules) and see if they make it necessary to get an appraisal. Gettting an appraisal is actually in your favor considering your home value has likely went up from the purchase price. They will use the appraisal value to determine your 'new' loan to value ratio and tell you how much you would need to pay (to bring the LTV to 78%) to have the PMI removed.
I say look into refinancing now because my dumb but paid $3000 to get my PMI removed, THEN refinanced (which would have removed the PMI) and I could have essentially held onto to more money. I didn't lose because the $3000 went to my equity, but it was unnecessary at the time, causing me to spend more money to obtain my goal.